Doc: Update examples on how to start debugging from the command line

Task-number: QTCREATORBUG-9484

Change-Id: Ic5da00c48eb185dc3cd842812e7c36cfefbb6776
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Leena Miettinen <riitta-leena.miettinen@digia.com>